Heat developable light-sensitive materials are well known in the art, and heat developable light-sensitive materials and their processes are described, for example, in Shashin Koqyo no Kiso (Fundamentals of Photographic Industry), pages 553 to 555, (1979, Koronasha); Eizo Joho (Image Information), page 40 (April 1978); Nebletts' Handbook of Photography and Reprography, pages 32 to 33 (7th edition, Van Nortrand Reinhold Company); U.S. Pat. Nos. 3,152,904, 3,301,678, 3,392,020, and 3,457,075; British Pat. Nos. 1,131,108, and 1,167,777; and Research Disclosure, June 1978, pages 9 to 15 (RD-17029).
Many techniques of providing color images have been suggested, including, for example, methods in which a color image is formed by combining the oxidation product of a developer and a coupler; methods in which a positive color image is formed by the light-sensitive silver-dye bleaching technique; and methods in which an image is formed by heat development, using a compound which has a dye portion and can release a mobile dye corresponding to or counter-corresponding to the reduction reaction of a silver halide to silver at a high temperature as disclosed, for example, in U.S. Pat. No. 4,500,626, European Patent Application Nos. 76,492A, and 79,056A, and Japanese Patent Application (OPI) Nos. 28928/83, and 26008/83 (the term "OPI", as used herein, refers to a "published unexamined Japanese patent application".
In these methods for forming an image, generally, to facilitate development when the heat-developable light-sensitive material is heated, an alkali agent or a precursor thereof, or an organic silver salt is incorporated in the heat developable light-sensitive material. However, a light-sensitive material containing a silver halide emulsion color-sensitized with a sensitizing dye together with an alkali agent or a precursor thereof, or an organic silver salt has the serious disadvantage that its sensitivity decreases during storage.
In the system containing a compound with a dye moiety which can release a mobile dye corresponding to or counter-corresponding to the reduction reaction of a silver halide to silver at a high temperature, when a color-sensitized silver halide is used, the storage stability of the light-sensitive material is very seriously decreased. It is assumed that because the dye releasing compound itself has a dye portion and properties similar to those of dyes, when it is used with a silver halide sensitized with a sensitizing dye, an interaction occurs between the dye releasing compound and the sensitizing dye adsorbed on the silver halide, and the sensitizing dye separates from the silver halide surface during the storage. This defect is a serious disadvantage in color light-sensitive materials and light-sensitive materials for electromagnetic radiation in regions outside the inherent sensitivity of silver halides.
Since photographic materials employing these image forming methods can be easily processed and can provide high quality images, they are used as printing materials in many fields, and can be used, for example, in the field of design of products such as electric appliances, automobiles, building materials, apparel, interior decoration, and crafted products; in the field of color scheme design of styles, designs, textiles, etc.; in the field of trade samples of real estate, decorative items, fashions, makeup, etc.; in the field of scientific analysis such as analysis of structures of molecular models, remote sensing, simulation, etc.; in the field of entertainment such as computer animation, computer art, etc.; in the field of medical images obtained by CCD autoscopes, microscopes, etc.; in the field of printing used for block copies, proofs, etc.; and in the field of duplicate prints, color telephotography, and high quality TV.